Illness absenteeism costs companies millions of dollars in lost revenue each year. Employee absenteeism has been called the “last unmanaged cost in business.” Journal of Occupational and Environmental Medicine, January 2001, Volume 3. According to a recent survey, “The Total Financial Impact of Employee Absences,” Employee Absenteeism, A Guide to Managing Abuse, Anne Coughlin, September 2004, the total cost of absence can equal as much as 36% of payroll when combined with the cost of absence related health care coverage. Of that figure, 9% accounts for unplanned absences. Planned absences, like vacations and holidays, average 26.6%. For a midsize business, illness absenteeism can drain millions of dollars per year from company profits.
Hand washing has been repeatedly demonstrated to reliably limit the spread of microorganisms that cause illness. However, immediate access to soap and water, and the time needed to correctly wash hands are significant barriers to this practice in the workplace, and especially for workers on manufacturing floors. Instant hand sanitizers can be of great use in situations where soap and water are not available for regular hand washing. Several studies have shown that illness absenteeism associated with transmissible pathogens is decreased by 15-50% when rinse free instant hand sanitizers are routinely used (cf. Dyer, et al., 2000; Hammond, et al., 2000, White, et al., 2001 Sandora, 2005). Therefore, using instant hand sanitizers in the workplace can save a Company millions of dollars annually.
The wide variety of instant hand sanitizers available to consumers may be grouped into two categories: alcohol-free and alcohol-containing. Of the former category, quaternary ammonium compounds are most frequently employed as the antimicrobial active chemical entity. Of the latter category, ethanol at a concentration range of 62-70% w/w is most readily available on the market. Both alcohol-free and alcohol-containing products generally are equally effective at reducing germs on the skin with a single use. With repeated use, alcohol-free products show a significant persistence of antimicrobial activity while alcohol-containing products appear to increase the skin's ability to carry disease-causing pathogens.
Microorganisms that spread from human skin can also adversely affect certain aspects of electronics manufacturing processes, and certain of these pose a danger to materials because they can destroy super-hard metal alloys, electric contacts and various polymers. Klintworth, et. al, 1999, reviewed the situation as it applied to electronic instrumentation in space-hardware applications. For example, during previous long-term manned spaceflight missions, more than 100 species of microorganisms were identified on surfaces of materials (bacteria and fungi). Among them were potentially pathogenic ones (saprophytes) capable of active growth on artificial substrates, as well as technophilic bacteria and fungi. Such biotic contaminants can degrade and destroy metals and polymers, resulting in failures and disruptions in the functioning of equipment and hardware. Russian long-term missions SALYUT and MIR have demonstrated that uncontrolled interactions of microorganisms with materials can ultimately lead to the appearance of technological and medical risks, significantly influencing safety and reliability characteristics of individual as well as whole systems and/or subsystems.
On a broader basis of consideration, electronic hardware cleanliness is focused on preventing contaminants. The core IPC standard for cleanliness is IPC-TM-650. IPC-A-610 (mostly section 10.4 for post-solder cleanliness) and J-STD-001 (section 8) derive some of their requirements from that standard. Some chemical contaminants will prevent solder wetting by forming a barrier between flux and the oxides. Others present a physical barrier to the flow of electricity after assembly (grease on gold contacts, for example). Ionic contamination can originate as the vestiges of the acids used to remove oxides, and as other ionic compounds introduced incidentally from workers' hands into circuitry. Examples of chemicals which present a high risk for interfering with electronic circuit function include, but are not limited to, amine or ammonium compounds, silicon and related compounds, and terpenes.
Parachlorometaxylenol (“PCMX”) has a phenolic chemical structure and is related to compounds such as cresol, carbolic acid, and hexachlorophene. PCMX is particularly effective against a wide variety of gram-positive and gram-negative bacteria. PCMX goes by a variety of other names, including chloroxylenol; 4-chloro-3,5xylenol; 4-chloro-3,5-dimethylphenol; 2-chloro-m-xylenol; 2-chloro-5-hydroxy-m-xylene; 2-chloro-5-hydroxy-m-xylene; 2-chloro-5-hydroxy-1,3-dimethylbenzene; 4-chlor-1-hydroxy-3,5-dimethyl benzene; and 3,5-dimethyl-4-chlorophenol.
PCMX is desirable for use as an antimicrobial active ingredient in rinse-free hand sanitizer compositions due to the fact that it is unlikely to interfere with electronic circuitry at concentrations resulting from incidental contact from workers' hands. However, PCMX-containing formulations are difficult to prepare due to the incompatibility of PCMX with many surfactants as well as other types of compounds. The efficacy of PCMX is often compromised by a variety of factors, such as additional ingredients (e.g., surfactants), pH level, and solubility.